title: Biochemical and biological analysis of Philodryas baroni (Baron's green racer; Dipsadidae) venom: relevance to the findings of human risk assessment.
abstract: Philodryas baroni--an attractively colored snake--has become readily available through the exotic pet trade. Most people consider this species harmless; however, it has already caused human envenomation. As little is known about the venom from this South American opisthoglyphous "colubrid" snake, herein, we studied its protein composition by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), as well as its effects on the hemostatic system. Both reducing and nonreducing SDS-PAGE analysis demonstrated that the venom exhibits greatest complexity in the range of 50-80 kDa. The venom displayed proteolytic activity toward azocollagen, with a specific activity of 75.5 U mg⁻¹, and rapidly hydrolyzed the Aα-chain of fibrinogen, exhibiting lower activity toward the Bβ- and γ-chains. The venom from P. baroni showed no platelet proaggregating activity per se, but it inhibited collagen- and thrombin-induced platelet aggregation. Prominent hemorrhage developed in mouse skin after intradermal injection of the crude venom, and its minimum hemorrhagic dose was 13.9 μg. When injected intramuscularly into the gastrocnemius of mice, the venom induced local effects such as hemorrhage, myonecrosis, edema, and leucocyte infiltration. Due to its venom toxicity shown herein, P. baroni should be considered dangerous to humans and any medically significant bite should be promptly reviewed by a qualified health professional.
authors.affiliation: 1Facultad de Ciencias Veterinarias, Universidad Nacional del Nordeste, Corrientes, Argentina.
authors.forename: M N
authors.initials: MN
authors.lastname: Sánchez
authors.forename: A
authors.initials: A
authors.lastname: Timoniuk
authors.forename: S
authors.initials: S
authors.lastname: Maruñak
authors.forename: P
authors.initials: P
authors.lastname: Teibler
authors.forename: O
authors.initials: O
authors.lastname: Acosta
authors.forename: M E
authors.initials: ME
authors.lastname: Peichoto
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D001118:Argentina; D003094:Collagen / Q000378:metabolism; D017812:Colubridae; D004305:Dose-Response Relationship, Drug; D010450:Endopeptidases / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D005340:Fibrinogen / Q000378:metabolism; D053878:Hemolytic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D006470:Hemorrhage / Q000139:chemically induced; D006801:Humans; D007271:Injections, Intradermal; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology; D009336:Necrosis; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D030162:Reptilian Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D018570:Risk Assessment; D012910:Snake Venoms / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D013379:Substrate Specificity
chemical_list: D000925:Anticoagulants; D053878:Hemolytic Agents; D010975:Platelet Aggregation Inhibitors; D030162:Reptilian Proteins; D012910:Snake Venoms; C464794:fibrinogen Aalpha; D005340:Fibrinogen; D003094:Collagen; D010450:Endopeptidases
keywords: Colubridae; Dipsadidae; coagulation; hemorrhage; platelets; rear-fanged snake